This invention relates to novel highly functionalized phosphine ligands as ancillary ligands in radiopharmaceuticals which are useful as imaging agents for the diagnosis of cardiovascular disorders such as thromboembolic disease or atherosclerosis, infectious disease and cancer and kits containing the same. The radiopharmaceuticals are comprised of highly functionalized phosphine ligated 99mTc-labeled biomolecules that selectively localize at sites of disease and thus allow an image to be obtained of the loci using gamma scintigraphy. The invention also provides methods of use of the radiopharmaceuticals as imaging agents for the diagnosis of cardiovascular disorders such as thromboembolic disease or atherosclerosis, infectious disease and cancer.
Radiopharmaceuticals are drugs containing a radionuclide, and are used routinely in nuclear medicine department for the diagnosis or therapy of various diseases. They are mostly small organic or inorganic compounds with definite composition. They can also be macromolecules such as antibodies and antibody fragments that are not stoichiometrically labeled with a radionuclide. Radiopharmaceuticals form the chemical basis for nuclear medicine, a group of techniques used for diagnosis and therapy of various diseases. The in vivo diagnostic information is obtained by intravenous injection of the radiopharmaceutical and determining its biodistribution using a gamma camera. The biodistribution of the radiopharmaceutical depends on the physical and chemical properties of the radiopharmaceutical and can be used to obtain information about the presence, progression, and the state of disease.
Radiopharmaceuticals can be divided into two primary classes: those whose biodistribution is determined exclusively by their chemical and physical properties; and those whose ultimate distribution is determined by their receptor binding or other biological interactions. The latter class is often called target-specific radiopharmaceuticals.
In general, a target specific radiopharmaceutical can be divided into four parts: a targeting molecule, a linker, a Bifunctional Chelator (BFC), and a radionuclide. The targeting molecule serves as a vehicle, which carries the radionuclide to the receptor site at the diseased tissue. The targeting molecules can be macromolecules such as antibodies. They can also be small biomolecules (Q): peptides, peptidomimetics, and non-peptide receptor ligands. The choice of biomolecule depends upon the targeted disease or disease state. The radionuclide is the radiation source. The selection of radionuclide depends on the intended medical use (diagnostic or therapeutic) of the radiopharmaceutical. Between the targeting molecule and the radionuclide is the BFC, which binds strongly to the metal ion via several coordination bonds and is covalently attached to the targeting molecule either directly or through a linker. Selection of a BFC is largely determined by the nature and oxidation state of the metallic radionuclide. The linker can be a simple hydrocarbon chain or a long poly(ethylene glycol) (PEG), which is often used for modification of pharmacokinetics. Sometimes, a metabolizeable linker is used to increase the blood clearance and to reduce the background activity, thereby improving the target-to-background ratio.
The use of metallic radionuclides offers many opportunities for designing new radiopharmaceuticals by modifying the coordination environment around the metal with a variety of chelators. The coordination chemistry of the metallic radionuclide will determine the geometry of the metal chelate and the solution stability of the radiopharmaceutical. Different metallic radionuclides have different coodination chemistries, and require BFCs with different donor atoms and ligand frameworks. For xe2x80x9cmetal essentialxe2x80x9d radiopharmaceuticals, the biodistribution is exclusively determined by the physical properties of the metal chelate. For target-specific radiopharmaceuticals, the xe2x80x9cmetal tagxe2x80x9d is not totally innocent because the target uptake and biodistribution will be affected by the metal chelate, the linker, and the targeting biomolecule. This is especially true for radiopharmaceuticals based on small molecules such as peptides due to the fact that in many cases the metal chelate contributes greatly to the overall size and molecular weight. Therefore, the design and selection of the BFC is very important for the development of a new radiopharmaceutical.
A BFC can be divided into three parts: a binding unit, a conjugation group, and a spacer (if necessary). An ideal BFC is that which is able to form a stable 99mTc complex in high yield at very low concentration of the BFC-Q conjugate. There are several requirements for an ideal BFC. First, the binding unit can selectively stabilize an intermediate or lower oxidation state of Tc so that the 99mTc complex is not subject to redox reactions; oxidation state changes are often accompanied by transchelation of 99mTc from a 99mTc-BFC-Ln-Q complex to the native chelating ligands in biological systems. Secondly, the BFC forms a 99mTc complex which has thermodynamic stability and kinetic inertness with respect to dissociation. Thirdly, the BFC forms a 99mTc complex with a minimum number of isomers since different isomeric forms of the 99MTc-chelate may have significant impact on the biological characteristics of the 99mTc-BFC-Ln-Q complex. Finally, the conjugation group can be easily attached to the biomolecule.
In simple technetium complex radiopharmaceuticals such as 99mTc-sestamibi, [99mTc(MIBI)6]+ (MIBI=2-methoxy-2-methylpropyl-isonitrile) and 99mTc-bicisate, [99mTcO(ECD)] (ECD=l,l-ethylene dicycteine diethyl ester), the ligand (MIBI or ECD) is always present in large excess. The main factor influencing the 99mTc-labeling kinetics is the nature of the donor atoms and the radiolabeling conditions. For receptor-based target specific radiopharmaceuticals, however, the use of large amount of BFCA-Ln-Q may result in receptor site saturation, blocking the docking of the 99mTc-labeled BFC-Ln-Q, as well as unwanted side effects. In order to avoid these problems, the concentration of the BFC-Ln-Q in the radiopharmaceutical kit has to be very low (10xe2x88x926-10xe2x88x925 M). Otherwise, a post-labeling purification is often needed to remove excess unlabeled BFC-Ln-Q, which is time consuming and thus not amenable for clinical use. Compared to the total technetium concentration (xcx9c5xc3x9710xe2x88x927 M) in 100 mCi of [99mTc]pertechnetate (24 h prior-elution), the BFC-Ln-Q is not in overwhelmingly excess. Therefore, the BFC attached to the biomolecule must have very high radiolabeling efficiency in order to achieve high specific activity, the amount of unlabeled BFC-Ln-Q conjugate used to synthesize the radiopharmaceutical. Various BFCs have been used for the 99mTc-labeling of biomolecules, and have been extensively reviewed (Hom, R. K. and Katzenellenbogen, J. A. Nucl. Med. Biol. 1997, 24, 485; Dewanjee, M. K. Semin. Nucl. Med. 1990, 20, 5; Jurisson, et al Chem. Rev. 1993, 93, 1137; Dilworth, J. R. and Parrott, S. J. Chem. Soc. Rev. 1998, 27, 43; Liu, et al Bioconj. Chem. 1997, 8, 621; Liu, et al Pure and Appl. Chem. 1991, 63, 427; Griffiths, et al Bioconj. Chem. 1992, 3, 91).
The use of hydrazines and hydrazides as BFCs to modify proteins for labeling with radionuclides has been recently disclosed in Schwartz et al U.S. Pat. No. 5,206,370. For labeling with technetium-99m, the hydrazino-modified protein is reacted with a reduced technetium species, formed by reacting [99mTc]pertechnetate with a reducing agent in the presence of a chelating dioxygen ligand. The technetium is bonded through what are believed to be hydrazino or diazenido linkages with the coordination sphere completed by the coligands such as glucoheptonate and lactate. Bridger et al European Patent Application No. 93302712.0 discloses a series of functionalized aminocarboxylates and their use for the radiolabeling of hydrazino-modified proteins. The improvements are manifested by shorter reaction times and higher specific activities for the radiolabeled protein. The best example is tricine.
Archer et al, European Patent application 90914225.9 discloses a series of 99mTc complexes having a ternary ligand system comprised of a hydrazino or diazenido ligand, a phosphine ligand and a halide, in which the substituents on the hydrazido or diazenido ligand and those phosphine ligand can be independently varied. This disclosure does not teach or suggest how to achieve the superior control of biological properties that will result from a ternary ligand system in which the substituents on the three types of ligands can be independently varied. In addition, the radiopharmaceuticals described by Archer et al are formed in low specific activity. Therefore, there remains a need for new ternary ligand systems which form radiopharmaceuticals with high specific activity.
U.S. Pat. No. 5,744,120 discloses novel ternary ligand radiopharmaceutical complexes composed of a water soluble phosphine as one of the three ligands. These ternary ligand complexes are formed in good yield, exhibit high solution stability, and exist in a minimal number of isomeric forms. The phosphine coligand can be functionalized to control the physicochemical properties of the ternary ligand complexes. The extent of such control is dependent on the degree of functionalization of the phosphine coligands. Thus, it is desirable and advantageous to discover ternary ligand complexes composed of highly functionalized, neutral water-soluble phosphine coligands.
The present invention provides novel ternary 99mTc radiopharmaceuticals composed of: chelator-modified biomolecules, including IIb/IIIa antagonists,tuftsin receptor antagonists, chemotactic peptides, vitronectin receptor antagonists and tyrosine kinase inhibitors, aminocarboxylates; and highly functionalized phosphine coligands. These radiopharmaceuticals are formed as minimal number of isomers, the relative ratio of which do not change with time. This invention provides novel radiopharmaceuticals and methods of using the same as imaging agents for the diagnosis of cardiovascular disorders such as thromboembolic disease or atherosclerosis, infectious disease and cancer. The radiopharmaceutical are comprised of highly functionalized phosphine ligated 99mTc labeled biomolecules that selectively localize at sites of disease and thus allow an image to be obtained of the loci using gamma scintigraphy. The present invention further provides kits for the preparation of the radiopharmaceuticals.
The highly functionalized phosphines contain hydroxy or polyhydroxy functionalities. These functionalities are of great interest because they can form neutral 99mTc complexes. The highly functionalized phosphines can contain carboxy or polycarboxy functionalities, which are used to increase hydrophilicity and to improve blood clearance and renal excretion of the 99mTc-labeled biomolecule. The highly functionalized phosphines can also contain metabolizeable ester or polyester functionalities and form neutral 99mTc complexes (if there is no charge on the biomolecule), which can cross the cell membrane and potentially bind intracellular receptors. Once inside the cell, hydrolysis of one or more ester groups forms a negatively charged 99mTc-species, which can not be easily diffused out from the cell. In this way, the target cell uptake may be significantly improved. On the other hand, if the ester group is hydrolyzed in the blood, the negatively charged 99mTc-species is expected to have faster and more renal clearance. Therefore, the introduction of the ester groups has two potential advantages: increase in target cell uptake and decrease in background.
[1] Thus in a first embodiment, the present invention provides an ancillary ligand (AL2) of the formula: 
or pharmaceutically acceptable salt form thereof; wherein:
R67 is independently selected, at each occurrence, from the group consisting of: C(O)R668, S(O)2R68, P(O) (OR68), C(O)NR68R69, S(O)2NR68R69, and C(O)OR68;
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, C2-10 alkenyl substituted with 1-5 R70 and 0-2 R70a, C2-10 alkynyl substituted with 1-5 R70 and 0-2 R70a, aryl substituted with 1-4 R70 and 0-1 R70a, C3-10 heterocycle substituted with 1-4 R70 and 0-1 R70a and C3-10 carbocycle substituted with 1-3 R70 and 0-2 R70a;
R69 is independently selected, at each occurrence, from the group consisting of: H, C1-10 alkyl substituted with 1-5 R70 and 0-2 R7Oa, C2-10 alkenyl substituted with 1-5 R70 and 0-2 R70a, C2-10 alkynyl substituted with 1-5 R70 and 0-2 R70a, aryl substituted with 1-3 R70 and 0-2 R70a, C3-10 heterocycle substituted with 1-4 R70 and 0-1 R70a, and C3-10 carbocycle substituted with 1-4 R70 and 0-1 R70a;
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, xe2x80x94CO2R71, xe2x80x94OC(xe2x95x90O)R71,xe2x80x94OC(xe2x95x90O)OR71, xe2x80x94OCH2CO2R71, xe2x80x94NR72C(xe2x95x90O)OR71, xe2x80x94SO2R71a, xe2x80x94SO3R71a, xe2x80x94NR72SO2R71a, xe2x80x94PO3R71a and C1-10 alkyl substituted with 1-5 xe2x80x94OR71;
R70a is independently selected, at each occurrence, from the group consisting of: xe2x95x90O, F, Cl, Br, I, xe2x80x94CF3, xe2x80x94CN, xe2x80x94N2, xe2x80x94C(xe2x95x90O)R71, xe2x80x94C(xe2x95x90O)N(R71)2, xe2x80x94N(R71)3+, xe2x80x94OC(xe2x95x90O)N(R71)2, xe2x80x94NR71C(xe2x95x90O)R71, xe2x80x94NR72C(xe2x95x90O)OR71a, xe2x80x94NR71C(xe2x95x90O)N(R71)2, xe2x80x94NR72SO2N(R71)2, xe2x80x94SO2N(R71)2, and xe2x80x94N(R71)2;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents;
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents; and,
R72 is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[2] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 wherein:
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, xe2x80x94SO3R71a, xe2x80x94CO2R71 and C1-10 alkyl substituted with 1-5 xe2x80x94OR71.
[3] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 wherein:
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
R70 is independently selected, at each occurrence, from the group consisting of: C1 alkyl substituted with xe2x80x94OR71, xe2x80x94OR71, xe2x80x94SO3R71a, and xe2x80x94CO2R71.
[4] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 wherein:
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: C1-6 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
R70 is independently selected, at each occurrence, from the group consisting of: C1 alkyl substituted with xe2x80x94OR71, xe2x80x94OR71, xe2x80x94SO3R71a, xe2x80x94CO2R71.
[5] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 wherein:
R67 is C(O)NR68R69;
R68 is C1-6 alkyl substituted with 1-5 R70 and 0-2 R70a;
R69 is hydrogen;
R70 is xe2x80x94OR71, xe2x80x94SO3R71a, xe2x80x94CO2R71;
R71 is H; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 1-5 hydroxyl substituents.
[6] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 1-3 R70;
R69 is hydrogen;
R70 is xe2x80x94OR71, xe2x80x94SO3R71a, or xe2x80x94CO2R71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl substituted with 1-2 hydroxyl substituents.
[7] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 of the formula: 
R67 is C(O)NR68R69;
R68 is C1-2 alkyl substituted with 1-2 R70;
R69 is hydrogen;
R70 is xe2x80x94OR71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl substituted with 1-2 hydroxyl substituents.
[8] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 1-3 R70;
R69 is hydrogen;
R70 is xe2x80x94SO3R71a or xe2x80x94CO2R71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl.
[9] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 0-3 xe2x80x94OR70 and 0-1 R70a;
R69 is hydrogen;
R70 is xe2x80x94CO2R71;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[10] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 of the formula: 
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: tetrohydropyranyl substituted with 1-4 R70 and 0-1 R70a, and tetrohydrofuranyl substituted with 1-3 R70 and 0-1 R71a;
R69 is hydrogen;
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, and C1 alkyl substituted with xe2x80x94OR71;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[11] In another embodiment, the present invention provides an ancillary ligand according to embodiment 1 selected from the group: 
or pharmaceutically acceptable salts thereof.
[12] In another embodiment, the present invention provides a radiopharmaceutical comprising an ancillary ligand according to any one of embodiments 1-11, chelated with a radionuclide selected from the group consisting of: 99mTc, 186Re and 188Re.
[13] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12,
wherein:
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with xe2x80x94OR711-4 R70 and 0-1 R70a;
R69 is H; and
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, SO3R71a, xe2x80x94CO2R7 and C1-6 alkyl substituted with 1-5 xe2x80x94OR71.
[14] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12 wherein:
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
[17] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12, wherein:
the ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 1-3 R70;
R69 is hydrogen;
R70 is xe2x80x94OR71, SO3R71a, or xe2x80x94CQ2R71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl substituted with 1-2 hydroxyl substituents.
[18] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12, wherein:
the ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C1-2 alkyl substituted with 1-2 R70;
R69 is hydrogen;
R70 is xe2x80x94OR71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl substituted with 1-2 hydroxyl substituents.
[19] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12, wherein:
the ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 1-3 R70;
R69 is hydrogen;
R70 is xe2x80x94SO3R71a or xe2x80x94CO2R71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl.
[20] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12, wherein:
the ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C13 alkyl substituted with 0-3R70 and 0-1 R70a;
R69 is hydrogen;
R70 is xe2x80x94CO2R71;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[21] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12, wherein:
the ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: tetrohydropyranyl substituted with 1-4 R70 and 0-1 R70a, and tetrohydrofuranyl substituted with 1-3 R70 and 0-1 R71a;
R69 is hydrogen;
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, and C1 alkyl substituted with xe2x80x94OR71;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[22] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 12,
wherein the ancillary ligand (AL2) is selected from the group consisting of: 
[23] In another embodiment, the present invention provides a radiopharmaceutical of formula:
(W)dxe2x80x2Lnxe2x80x94Chxe2x80x2lxxe2x80x94Mt (AL1)y(AL2)z xe2x80x83xe2x80x83(1) 
or pharmaceutically acceptable salts thereof wherein,
AL2 an ancillary ligand of any one of embodiments 1-11;
AL1 is a first ancillary ligand and is a dioxygen ligand or a functionalized aminocarboxylate;
Q is a biologically active group;
dxe2x80x2 is 1 to 20;
Ln is a linking group of formula:
M1xe2x80x94[Y1(CR55R56)f(Z1)fxe2x80x3Y2]fxe2x80x2xe2x80x94M2, 
M1 is xe2x80x94[(CH2)gZ1]gxe2x80x2xe2x80x94(CR55R56)gxe2x80x3xe2x80x94;
M2 is xe2x80x94(CR55R56)gxe2x80x3xe2x80x94[Z1(CH2)g]gxe2x80x2xe2x80x94;
g is independently 0-10;
gxe2x80x2 is independently 0-1;
gxe2x80x3 is independently 0-10;
f is independently 0-10;
fxe2x80x2 is independently 0-10;
fxe2x80x3 is independently 0-1;
Y1 and Y2, at each occurrence, are independently selected from: a bond, O, NR56, Cxe2x95x90O, C(xe2x95x90O)O,
OC(xe2x95x90O)O, C(xe2x95x90O)NHxe2x80x94, Cxe2x95x90NR56, S, SO, S2, SO3, NHC(xe2x95x90O), (NH)2C(xe2x95x90O), and (NH)2Cxe2x95x90S;
Z1 is independently selected at each occurrence from a C6-C14 saturated, partially saturated, or aromatic carbocyclic ring system, substituted with 0-4 R57; and a heterocyclic ring system, optionally substituted with 0-4 R57;
R55 and R56 are independently selected at each occurrence from: H, C1-C10 alkyl substituted with 0-5 R57, and alkaryl wherein the aryl is substituted with 0-5 R57;
R57 is independently selected at each occurrence from the group: H, OH, NHR58, C(xe2x95x90O)R58, OC(xe2x95x90O)R58, OC(xe2x95x90O)OR58, C(xe2x95x90O)OR58, C(xe2x95x90O)NR58, xe2x80x94CN, SR58, SOR58, SO2R58, NHC(xe2x95x90O)R58, NHC(xe2x95x90O)NHR58, and NHC(xe2x95x90S)NHR58,
alternatively, when attached to an additional molecule Q, R57 is independently selected at each occurrence from the group: O, NR58, Cxe2x95x90O, C(xe2x95x90O)O, OC(xe2x95x90O)O, C(xe2x95x90O)N, Cxe2x95x90NR58, S, SO, S2, SO3, NHC(xe2x95x90O), (NH)2C(xe2x95x90O), and (NH)2Cxe2x95x90S;
R58 is independently selected at each occurrence from the group: H, C1-C6 alkyl, benzyl, and phenyl;
x, y and z are independently 1 or 2;
Mt is a transition metal radionuclide selected from the group: 99mTc, 186Re and 188Re;
Ch xe2x80x2is a radionuclide metal chelator coordinated to transition metal radionuclide Mt, and is independently selected at each occurrence, from the group: R40Nxe2x95x90N+xe2x95x90, R40R41 Nxe2x80x94Nxe2x95x90, and R40Nxe2x95x90N(H)xe2x80x94;
R40 is independently selected at each occurrence from the group: a bond to Ln, C1-C10 alkyl substituted with 0-3 R52, aryl substituted with 0-3 R52, cycloaklyl substituted with 0-3 R52 heterocycle substituted with 0- 3 R52, heterocycloalkyl substituted with 0-3 R52, aralkyl substituted with 0-3 R52 and alkaryl substituted with 0-3 R52;
R41 is independently selected from the group: H, aryl substituted with 0-3 R52, C1-C10 alkyl substituted with 0-3 R52 and a heterocycle substituted with 0-3 R52;
R52 is independently selected at each occu rrence from the group: a bond to Ln, xe2x95x90O, F, Cl, Br, I, xe2x80x94CF3, xe2x80x94CN, xe2x80x94CO2R53, xe2x80x94C(xe2x95x90O)R53, xe2x80x94C(xe2x95x90O)N(R53)2, xe2x80x94CHO, xe2x80x94CH2OR53, xe2x80x94OC(xe2x95x90O)R53, xe2x80x94OC(xe2x95x90O)OR53a, xe2x80x94OR53, xe2x80x94OC(xe2x95x90O)N(R53)2, xe2x80x94NR53C(xe2x95x90O)R53, xe2x80x94N(R53)3+, xe2x80x94NR54C(xe2x95x90O)OR53a, xe2x80x94NR53C(xe2x95x90O)N(R53)2, xe2x80x94NR54SO2N(R53)2, xe2x80x94NR54SO2R53a, xe2x80x94SO3H, xe2x80x94SO2R53a, xe2x80x94SR53, xe2x80x94S(xe2x95x90O)R53a, xe2x80x94SO2N(R53)2, xe2x80x94N(R53)2, xe2x80x94NHC(xe2x95x90NH)NHR53, xe2x80x94C(xe2x95x90NH)NHR53, xe2x95x90NOR53, NO2, xe2x80x94C(xe2x95x90O)NHOR53, xe2x80x94C(xe2x95x90O)NHNR53R53a, xe2x80x94OCH2CO2H, and 2-(1-morpholino)ethoxy;
R53, R53a, and R54 are each independently selected at each occurrence from the group: H, C1-C6 alkyl, and a bond to Ln.
[24] In another embodiment, the present invention provides a radiopharmaceutical embodiment 23 wherein:
Q is a biomolecule selected from the group: IIb/IIIa receptor antagonists, IIb/IIIa receptor ligands, fibrin binding peptides, leukocyte binding peptides, chemotactic peptides, somatostatin analogs, selectin binding peptides, vitronectin receptor antagonists, and tyrosine kinase inhibitors;
dxe2x80x2 is 1 to 3;
Ln is:
xe2x80x94(CR55R56)gxe2x80x2xe2x80x94[Y1(CR55R56)fxe2x80x2]xe2x80x94(CR55R56)gxe2x80x3xe2x80x94, 
gxe2x80x3 is 0-5;
f is 0-5;
fxe2x80x2 is 1-5;
Y1 and Y2, at each occurrence, are independently selected from: O, NR56, Cxe2x95x90O, C(xe2x95x90O)O, OC(xe2x95x90O)O, C(xe2x95x90O)NH, Cxe2x95x90NR56, S, SO, S2, SO3, NHC(xe2x95x90O), (NH)2C(xe2x95x90O), and (NH)2Cxe2x95x90S;
R55 and R56 are independently selected at each occurrence from: H, C1-C10 alkyl and alkaryl;
x and y are 1;
Mt is 99mTc;
Chxe2x80x2 is R40Nxe2x95x90N+xe2x95x90 or R40R41Nxe2x80x94Nxe2x95x90;
R40 is independently selected at each occurrence from the group: aryl substituted with 0-3 R52, and heterocycle substituted with 0-3 R52;
R41 is independently selected from the group: H, aryl substituted with 0-1 R52, C1-C3 alkyl substituted with 0-1 R521 and a heterocycle substituted with 0-1 R52;
R52 is independently selected at each occurrence from the group: a bond to Ln, xe2x80x94CO2R53, xe2x80x94CH20R53, xe2x80x94SO3H, xe2x80x94SO2R53a, xe2x80x94N(R53)2, xe2x80x94N(R53)3+, xe2x80x94NHC(xe2x95x90NH)NHR53, and xe2x80x94OCH2CO2H;
R53 and R53a are each independently selected at each occurrence from the group: H and C1-C3 alkyl;
AL1 is a functionalized aminocarboxylate;
AL2 is an ancillary ligand of formula: 
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94R71, xe2x80x94SO3R71a, or xe2x80x94CO2R71, and C1-6 alkyl substituted with 1-5 xe2x80x94OR71.
[25] In another embodiment, the present invention provides a radiopharmaceutical embodiment 23 wherein:
Q is a biomolecule selected from the group: lIb/IIIa receptor antagonists and chemotactic peptides;
dxe2x80x2 is 1;
Y1 and Y2, at each occurrence, are independently selected from: O, NR56, Cxe2x95x90O, C(xe2x95x90O)O, OC(xe2x95x90O)O, C(xe2x95x90O)NH, Cxe2x95x90NR56, NHC(xe2x95x90O), and (NH)2C(xe2x95x90O);
R55 and R56 are H;
z is 1;
R40 is a heterocycle substituted with R52;
R41 is H;
R52 is a bond to Ln;
AL1 is tricine;
AL2 is an ancillary ligand of formula: 
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: C1-10 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
R70 and is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, xe2x80x94SO3R71a, xe2x80x94CO2R71 and C1-10 alkyl substituted with 1-5 xe2x80x94OR71.
[26] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is an ancillary ligand of formula: 
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: C1-6 alkyl substituted with 1-5 R70 and 0-2 R70a, and C5-6 heterocyclyl substituted with 1-4 R70 and 0-1 R70a;
R69 is H; and
R70 is xe2x80x94OR71, xe2x80x94SO3R71a, xe2x80x94CO2R71.
[27] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is an ancillary ligand of formula: 
R67 is C(O)NR68R69;
R68 is C1-6 alkyl substituted with 1-5 R70 and 0-2 R70a;
R69 is hydrogen;
R70 is xe2x80x94OR71, xe2x80x94SO3R71a, xe2x80x94CO2R71;
R71 is H; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 1-5 hydroxyl substituents.
[28] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 1-3 R70;
R69 is hydrogen;
R70 is xe2x80x94R71, xe2x80x94SO3R71a, or xe2x80x94CO2R71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl substituted with 1-2 hydroxyl substituents.
[29] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C1-2 alkyl substituted with 1-2 R70;
R69 is hydrogen;
R70 is xe2x80x94OR71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl substituted with 1-2 hydroxyl substituents.
[30] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is C1-3 alkyl substituted with 1-3 R70;
R69 is hydrogen;
R70 is xe2x80x94SO3R71a or xe2x80x94CO2R71; and
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl.
[31] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 C1-3 alkyl substituted with 1-3 R70 and 0-3 R70a;
R69 is hydrogen;
R70 is xe2x80x94CO2R71;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[32] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is ancillary ligand is of the formula: 
R67 is C(O)NR68R69;
R68 is independently selected, at each occurrence, from the group consisting of: tetrohydropyranyl substituted with 1-4 R70 and 0-1 R70a, and tetrohydrofuranyl substituted with 1-3 R70 and 0-1 R71a;
R69 is hydrogen;
R70 is independently selected, at each occurrence, from the group consisting of: xe2x80x94OR71, and C1 alkyl substituted with 1 xe2x80x94OR71;
R71 is independently selected, at each occurrence, from the group consisting of: H and C1-2 alkyl; and
R71a is independently selected, at each occurrence, from the group consisting of: H and C1-C6 alkyl substituted with 0-5 hydroxyl substituents.
[33] In another embodiment, the present invention provides a radiopharmaceutical according to embodiment 23, wherein:
AL2 is selected from the group: 
or pharmaceutically acceptable salts thereof.
[34] In another embodiment, the present invention provides a radiopharmaceutical of embodiment 23 wherein:
Q is 
dxe2x80x2 is 1;
Ln is attached to Q at the carbon atom designated with a * and has the formula:
xe2x80x94(Cxe2x95x90O)NH(CH2)5C(xe2x95x90O)NHxe2x80x94; 
Chxe2x80x2 is 
and is attached to Ln at the carbon atom designated with a *;
Mt is 99mTc; and
AL1 is tricine.
[35] In another embodiment, the present invention provides a radiopharmaceutical according to any one of embodiments 23-34 wherein the Q-Ln moiety is selected from the group: 
, wherein * indicates the point of attachment to the chelator moiety (Ch).
[36] In another embodiment, the present invention provides a radiopharmaceutical according to any one of embodiment 23-34, wherein the radiopharmaceutical is selected from the group: 
or a pharmaceutically acceptable salt form thereof.
[37] In another embodiment, the present invention provides a method for radioimaging a patient comprising:
(i) administering to said patient an effective amount of a radiopharmaceutical according to any one of embodiment 23-36; and
(ii) scanning the patient using a radioimaging device.
[38] In another embodiment, the present invention provides a method for visualizing sites of platelet deposition in a patient by radioimaging, comprising:
(i) administering to said patient an effective amount of a radiopharmaceutical according to any one of embodiment 23-36; and
(ii) scanning the patient using a radioimaging device;
wherein Q is a IIb/IIIa receptor ligand or fibrin binding peptide.
[39] In another embodiment, the present invention provides a method of determining platelet deposition in a patient comprising:
(i) administering to said patient a radiopharmaceutical according to any one of embodiment 23-36; and
(ii) imaging said patient;
wherein Q is a IIb/IIIa receptor ligand or fibrin binding peptide.
[40] In another embodiment, the present invention provides a method of diagnosing a disorder associated with platelet deposition in a patient comprising:
(i) administering to said patient a radiopharmaceutical composition according to any one of embodiment 23-36; and
(ii) imaging said patient;
wherein Q is a IIb/IIIa receptor ligand or fibrin binding peptide.
[41] In another embodiment, the present invention provides a method of diagnosing thromboembolic disorders or atherosclerosis in a patient, comprising:
(i) administering to said patient a radiopharmaceutical according to any one of embodiment 23-36; and
(ii) generating a radioimage of at least a part of said patient""s body;
wherein Q is a IIb/IIIa receptor ligand or fibrin binding peptide.
[42] In another embodiment, the present invention provides a method of diagnosing infection, inflammation or transplant rejection in a patient, comprising:
(i) administering to said patient a radiopharmaceutical according to any one of embodiment 23-36; and
(ii) generating a radioimage of at least a part of said patient""s body;
wherein Q is selected from the group consisting of a leukocyte binding peptide, a chemotactic peptide, and a LTB4 receptor antagonist.
[43] In another embodiment, the present invention provides a method of detecting new angiogenic vasculature in a patient, comprising:
(i) administering to said patient a radiopharmaceutical according to any one of embodiment 23-36; and
(ii) generating a radioimage of at least a part of said patient""s body;
wherein Q is a vitronectin receptor antagonist, a somatostatin analog, or a growth factor receptor antagonist.
[44] In another embodiment, the present invention provides a kit for forming a radiopharmaceutical complex comprising the following components:
(i) an ancillary ligand according to any one of embodiment 1-11;
(ii) optionally a reducing agent; and
(iii) instructions for reacting the components of said kit with a radionuclide solution.
[45] In another embodiment, the present invention provides a kit for preparing a radiopharmaceutical comprising:
(a) a predetermined quantity of a sterile, pharmaceutically acceptable first ancillary ligand, AL2, according to any one of embodiment 1-11;
(b) a predetermined quantity of a sterile, pharmaceutically acceptable reagent of formula:
(Q)dxe2x80x2Lnxe2x80x94Ch; 
(c) a predetermined quantity of a sterile, pharmaceutically acceptable second ancillary ligand, AL1, selected from the group: a dioxygen ligand and a functionalized aminocarboxylate;
(d) a predetermined quantity of a sterile, pharmaceutically acceptable reducing agent; and
(e) optionally, a predetermined quantity of one or more sterile, pharmaceutically acceptable components selected from the group: transfer ligands, buffers, lyophilization aids, stabilization aids, solubilization aids and bacteriostats;
wherein:
Q is a biomolecule;
dxe2x80x2 is 1 to 20;
Ln is a linking group of formula:
M1xe2x80x94[Y1(CR55R56)f(Z1)fxe2x80x3Y2]fxe2x80x2xe2x80x94M2, 
M1 is xe2x80x94[(CH2)gZ1]gxe2x80x2-(CR55R56)gxe2x80x3xe2x80x94;
M2 is xe2x80x94(CR55R56)gxe2x80x2xe2x80x94[Z1(CH2)g]gxe2x80x3xe2x80x94;
g is independently 0-10;
gxe2x80x2 is independently 0-1;
gxe2x80x3 is independently 0-10;
f is independently 0-10;
fxe2x80x2 is independently 0-10;
fxe2x80x3 is independently 0-1;
Y1 and Y2, at each occurrence, are independently selected from: a bond, O, NR56, Cxe2x95x90O, C(xe2x95x90O)O, OC(xe2x95x90O)O, C(xe2x95x90O)NHxe2x80x94, Cxe2x95x90NR56, S, SO, SO2, SO3, NHC(xe2x95x90O), (NH)2C(xe2x95x90O), and (NH)2Cxe2x95x90S;
Z1 is independently selected at each occurrence from a C6-C14 saturated, partially saturated, or aromatic carbocyclic ring system, substituted with 0-4 R57; and a heterocyclic ring system, optionally substituted with 0-4 R57;
R55 and R56 are independently selected at each occurrence from: H, C1-C10 alkyl substituted with 0-5 R57, and alkaryl wherein the aryl is substituted with 0-5 R57;
R57 is independently selected at each occurrence from the group: H, OH, NHR58, C(xe2x95x90O)R58, OC(xe2x95x90O)R58, OC(xe2x95x90O)OR58, C(xe2x95x90O)OR58, C(xe2x95x90O)NR58, xe2x80x94CN, SR58, SOR58, SO2R58, NHC(xe2x95x90O)R58, NHC(xe2x95x90O)NHR58, and NHC(xe2x95x90S)NHR58,
alternatively, when attached to an additional molecule Q, R57 is independently selected at each occurrence from the group: O, NR58, Cxe2x95x90O, C(xe2x95x90O)O, OC(xe2x95x90O)O, C(xe2x95x90O)N, Cxe2x95x90NR58, S, SO, SO2, SO3, NHC(xe2x95x90O), (NH)2C(xe2x95x90O), and (NH)2Cxe2x95x90S;
R58 is independently selected at each occurrence from the group: H, C1-C6 alkyl, benzyl, and phenyl; x, y and z are independently 1 or 2;
Mt is a transition metal radionuclide selected from the group: 99mTc, 186Re and 188 Re;
Chxe2x80x2 is a radionuclide metal chelator coordinated to transition metal radionuclide Mt, and is independently selected at each occurrence, from the group: R40Nxe2x95x90N+xe2x95x90, R40R41Nxe2x80x94Nxe2x95x90, and R40Nxe2x95x90N (H)xe2x80x94;
R40 is independently selected at each occurrence from the group: a bond to Ln, C1-C10 alkyl substituted with 0-3 R52, aryl substituted with 0-3 R52, cycloaklyl substituted with 0-3 R52, heterocycle substituted with 0-3 R52, heterocycloalkyl substituted with 0-3 R52, aralkyl substituted with 0-3 R52 and alkaryl substituted with 0-3 R52;
R41 is independently selected from the group: H, aryl substituted with 0-3 R52, C1-C10 alkyl substituted with 0-3 R52, and a heterocycle substituted with 0-3 R52;
R52 is independently selected at each occurrence from the group: a bond to Ln, xe2x95x90O, F, Cl, Br, I, xe2x80x94CF3, xe2x80x94CN, xe2x80x94CO2R53, xe2x80x94C(xe2x95x90O)R53, xe2x80x94C(xe2x95x90O)N(R53)2, xe2x80x94CHO, xe2x80x94CH2OR53, xe2x80x94OC(xe2x95x90O)R53, xe2x80x94OC(xe2x95x90O)OR53a, xe2x80x94OR53, xe2x80x94OC(xe2x95x90O)N(R53)2, xe2x80x94NR53C(xe2x95x90O)R53, xe2x80x94N(R53)3+, xe2x80x94NR54C(xe2x95x90O)OR53a, xe2x80x94NR53C(xe2x95x90O)N(R53)2, xe2x80x94NR54SO2N(R53)2, xe2x80x94NR54SO2R53a, xe2x80x94SO3H, xe2x80x94SO2R53a, xe2x80x94SR53, xe2x80x94S(xe2x95x90O)R53a, xe2x80x94SO2N(R53)2, xe2x80x94N(R53)2, xe2x80x94NHC(xe2x95x90NH)NHR53, xe2x80x94C(xe2x95x90NH)NHR53, xe2x95x90NOR53, NO2, xe2x80x94C(xe2x95x90O)NHOR53, xe2x80x94C(xe2x95x90O)NHNR53R53a, xe2x80x94OCH2CO2H, and 2-(1-morpholino)ethoxy; and
R53, R53a, and R54 are each independently selected at each occurrence from the group: H, C1-C6 alkyl, and a bond to Ln.
[46] In another embodiment, the present invention provides a kit according to embodiment 45, wherein the Q-Ln moiety is selected from the group: 
wherein * indicates the point of attachment to the chelator moiety (Ch).
[47] In another embodiment, the present invention provides a diagnostic composition comprising a diagnostic effective amount of the radiopharmaceutical according to any one of embodiments 23-36 and a pharmaceutically acceptable carrier.
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination.
As used herein, xe2x80x9cdiagnostic effective amountxe2x80x9d is meant to describe an amount of composition according to the present invention effective in producing the desired diagnostic effect.
As used herein, xe2x80x9calkylxe2x80x9d is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms. Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, and s-pentyl. xe2x80x9cHaloalkylxe2x80x9d is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms, substituted with 1 or more halogen (for example xe2x80x94CVFw where v xe2x95x901 to 3 and w=1 to (2v+1)). Examples of haloalkyl include, but are not limited to, trifluoromethyl, trichloromethyl, pentafluoroethyl, and pentachloroethyl.
As used herein, xe2x80x9calkoxyxe2x80x9d represents an alkyl group as defined above with the indicated number of carbon atoms attached through an oxygen bridge. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, s-butoxy, t-butoxy, n-pentoxy, and s-pentoxy.
As used herein, xe2x80x9calkenylxe2x80x9d is intended to include hydrocarbon chains of either a straight or branched configuration and one or more unsaturated carbon-carbon bonds which may occur in any stable point along the chain, such as ethenyl and propenyl.
As used herein, xe2x80x9calkynylxe2x80x9d, is intended to include hydrocarbon chains of either a straight or branched configuration and one or more triple carbon-carbon bonds which may occur in any stable point along the chain, such as ethynyl and propynyl.
xe2x80x9cHaloxe2x80x9d or xe2x80x9chalogenxe2x80x9d as used herein refers to fluoro, chloro, bromo, and iodo; and xe2x80x9ccounterionxe2x80x9d is used to represent a small, negatively charged species such as chloride, bromide, hydroxide, acetate, and sulfate.
The term xe2x80x9ccarbocyclexe2x80x9d or xe2x80x9ccarbocyclic residuexe2x80x9d as used herein, is intended to mean any stable 3- to 7-membered monocyclic or bicyclic or 7-to 13-membered bicyclic or tricyclic, any of which may be saturated (i.e. a cycloalkyl moiety), partially unsaturated saturated (i.e. a cycloalkenyl moiety), or aromatic (i.e. an aryl moiety). Examples of such carbocycles include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, cyclooctyl, [3.3.0]bicyclooctane, [4.3.0]bicyclononane, [4.4.0]bicyclodecane, [2.2.2]bicyclooctane, fluorenyl, phenyl, naphthyl, indanyl, adamantyl, and tetrahydronaphthyl.
The term xe2x80x9ccycloalkylxe2x80x9d as used herein, means a non-aromatic mono- or multicyclic ring system of about 3 to about 10 carbon atoms, preferably of about 5 to about 10 carbon atoms. Preferred ring sizes of rings of the ring system include about 5 to about 6 ring atoms. Exemplary monocyclic cycloalkyl include cyclopentyl, cyclohexyl, cycloheptyl, and the like. Exemplary multicyclic cycloalkyl include 1-decalin, norbornyl, adamant-(1- or 2-)yl, and the like.
The term xe2x80x9ccycloalkenylxe2x80x9d as used herein, means a non-aromatic mono- or multicyclic ring system of about 3 to about 10 carbon atoms, preferably of about 5 to about 10 carbon atoms, and which contains at least one carbon-carbon double bond. Preferred ring sizes of rings of the ring system include about 5 to about 6 ring atoms. Exemplary monocyclic cycloalkenyl include cyclopentenyl, cyclohexenyl, cycloheptenyl, and the like. An exemplary multicyclic cycloalkenyl is norbornylenyl.
The term xe2x80x9carylxe2x80x9d as used herein, means an aromatic monocyclic or multicyclic ring system of about 6 to about 14 carbon atoms, preferably of about 6 to about 10 carbon atoms. Exemplary aryl groups include phenyl or naphthyl, or phenyl substituted or naphthyl substituted.
The term xe2x80x9cheterocyclexe2x80x9d or xe2x80x9cheterocyclic systemxe2x80x9d as used herein, is intended to mean a stable 5-to 7-membered monocyclic or bicyclic or 7-to 10-membered bicyclic heterocyclic ring which is a saturated heterocyclic ring (i.e. a heterocyclyl moiety), a partially unsaturated heterocyclic ring (i.e. a heterocyclenyl moiety), or an unsaturated heterocyclic ring (i.e. a heteroaryl moiety), and which consists of carbon atoms and from 1 to 4 heteroatoms independently selected from the group consisting of N, O and S and including any bicyclic group in which any of the above-defined heterocyclic rings is fused to a benzene ring. The nitrogen and sulfur heteroatoms may optionally be oxidized. The heterocyclic ring may be attached to its pendant group at any heteroatom or carbon atom which results in a stable structure. The heterocyclic rings described herein may be substituted on carbon or on a nitrogen atom if the resulting compound is stable. A nitrogen in the heterocycle may optionally be quaternized. It is preferred that when the total number of S and O atoms in the heterocycle exceeds 1, then these heteroatoms are not adjacent to one another. It is preferred that the total number of S and O atoms in the heterocycle is not more than 1.
Examples of heterocycles include, but are not limited to, acridinyl, azocinyl, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benztriazolyl, benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl, dihydrofuro[2,3-b]tetrahydrofuran, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H-indazolyl, indolenyl, indolinyl, indolizinyl, indolyl, 3H-indolyl, isobenzofuranyl, isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl, isothiazolyl, isoxazolyl, methylenedioxyphenyl, morpholinyl, naphthyridinyl, octahydroisoquinolinyl, oxadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidinyl, oxazolyl, oxazolidinyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazinyl, phthalazinyl, piperazinyl, piperidinyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridooxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, 2H-pyrrolyl, pyrrolyl, quinazolinyl, quinolinyl, 4H-quinolizinyl, quinoxalinyl, quinuclidinyl, tetrahydrofuranyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, 6H-1,2,5-thiadiazinyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl, triazinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,5-triazolyl, 1,3,4-triazolyl, and xanthenyl. Preferred heterocycles include, but are not limited to, pyridinyl, furanyl, thienyl, pyrrolyl, pyrazolyl, pyrrolidinyl, imidazolyl, indolyl, benzimidazolyl, 1H-indazolyl, oxazolidinyl, benzotriazolyl, benzisoxazolyl, oxindolyl, benzoxazolinyl, and isatinoyl. Also included are fused ring and spiro compounds containing, for example, the above heterocycles.
The term xe2x80x9caromatic heterocyclic systemxe2x80x9d or xe2x80x9cheteroarylxe2x80x9d as used herein, means an aromatic monocyclic or multicyclic ring system of about 5 to about 14 carbon atoms, preferably about 5 to about 10 carbon atoms, in which one or more of the carbon atoms in the ring system is/are hetero element(s) other than carbon, for example nitrogen, oxygen or sulfur. Preferred ring sizes of rings of the ring system include about 5 to about 6 ring atoms. The designation of the aza, oxa or thia as a prefix before heteroaryl define that at least a nitrogen, oxygen or sulfur atom is present respectively as a ring atom. It is preferred that the total number of S and O atoms in the aromatic heterocycle is not more than 1. A nitrogen atom of an heteroaryl may be a basic nitrogen atom and may also be optionally oxidized to the corresponding N-oxide. Heteroaryl as used herein includes by way of example and not limitation those described in Paquette, Leo A.; xe2x80x9cPrinciples of Modern Heterocyclic Chemistryxe2x80x9d (W. A. Benjamin, New York, 1968), particularly Chapters 1, 3, 4, 6, 7, and 9; xe2x80x9cThe Chemistry of Heterocyclic Compounds, A series of Monographsxe2x80x9d (John Wiley and Sons, New York, 1950 to present), in particular Volumes 13, 14, 16, 19, and 28; and xe2x80x9cJ. Am. Chem. Soc. xe2x80x9d, 82:5566 (1960). Exemplary heteroaryl and substituted heteroaryl groups include pyrazinyl, thienyl, isothiazolyl, oxazolyl, pyrazolyl, furazanyl, pyrrolyl, 1,2,4-thiadiazolyl, pyridazinyl, quinoxalinyl, phthalazinyl, imidazo[1,2-a]pyridine, imidazo[2,1-b]thiazolyl, benzofurazanyl, azaindolyl, benzimidazolyl, benzothienyl, thienopyridyl, thienopyrimidyl, pyrrolopyridyl, imidazopyridyl, benzoazaindole, 1,2,4-triazinyl, benzthiazolyl, furanyl, imidazolyl, indolyl, indolizinyl, isoxazolyl, isoquinolinyl, isothiazolyl, oxadiazolyl, pyrazinyl, pyridazinyl, pyrazolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, 1,3,4-thiadiazolyl, thiazolyl, thienyl and triazolyl.
The term xe2x80x9cheterocyclenylxe2x80x9d as used herein, means a non-aromatic monocyclic or multicyclic hydrocarbon ring system of about 3 to about 10 carbon atoms, preferably about 5 to about 10 carbon atoms, in which one or more of the carbon atoms in the ring system is/are hetero element(s) other than carbon, for example nitrogen, oxygen or sulfur atoms, and which contains at least one carbon-carbon double bond or carbon-nitrogen double bond. It is preferred that the total number of S and O atoms in the heterocyclenyl is not more than 1. Preferred ring sizes of rings of the ring system include about 5 to about 6 ring atoms. The designation of the aza, oxa or thia as a prefix before heterocyclenyl define that at least a nitrogen, oxygen or sulfur atom is present respectively as a ring atom. The nitrogen atom of an heterocyclenyl may be a basic nitrogen atom. The nitrogen or sulphur atom of the heterocyclenyl may also be optionally oxidized to the corresponding N-oxide, S-oxide or S,S-dioxide. xe2x80x9cHeterocyclenylxe2x80x9d as used herein includes by way of example and not limitation those described in Paquette, Leo A. xe2x80x9cPrinciples of Modern Heterocyclic Chemistryxe2x80x9d (W. A. Benjamin, New York, 1968), particularly Chapters 1, 3, 4, 6, 7, and 9; xe2x80x9cThe Chemistry of Heterocyclic Compounds, A series of Monographsxe2x80x9d (John Wiley and Sons, New York, 1950 to present), in particular Volumes 13, 14, 16, 19, and 28; and xe2x80x9cJ. Am. Chem. Soc. xe2x80x9d, 82:5566 (1960). Exemplary monocyclic azaheterocyclenyl groups include 1,2,3,4- tetrahydrohydropyridine, 1,2-dihydropyridyl, 1,4-dihydropyridyl, 1,2,3,6-tetrahydropyridine, 1,4,5,6-tetrahydropyrimidine, 2-pyrrolinyl, 3-pyrrolinyl, 2-imidazolinyl, 2-pyrazolinyl, and the like. Exemplary oxaheterocyclenyl groups include 3,4-dihydro-2H-pyran, dihydrofuranyl, and fluorodihydrofuranyl. Preferred is dihydrofuranyl. An exemplary multicyclic oxaheterocyclenyl group is 7-oxabicyclo[2.2.1]heptenyl. Preferred monocyclic thiaheterocycleny rings include dihydrothiophenyl and dihydrothiopyranyl; more preferred is dihydrothiophenyl.
The term xe2x80x9cheterocyclylxe2x80x9d as used herein, means a non-aromatic saturated monocyclic or multicyclic ring system of about 3 to about 10 carbon atoms, preferably about 5 to about 10 carbon atoms, in which one or more of the carbon atoms in the ring system is/are hetero element(s) other than carbon, for example nitrogen, oxygen or sulfur. It is preferred that the total number of S and O atoms in the aromatic heterocycle is not more than 1. Preferred ring sizes of rings of the ring system include about 5 to about 6 ring atoms. The designation of the aza, oxa or thia as a prefix before heterocyclyl define that at least a nitrogen, oxygen or sulfur atom is present respectively as a ring atom. The nitrogen atom of an heterocyclyl may be a basic nitrogen atom. The nitrogen or sulphur atom of the heterocyclyl may also be optionally oxidized to the corresponding N-oxide, S-oxide or S,S-dioxide. xe2x80x9cHeterocyclylxe2x80x9d as used herein includes by way of example and not limitation those described in Paquette, Leo A. ; xe2x80x9cPrinciples of Modern Heterocyclic Chemistryxe2x80x9d (W. A. Benjamin, New York, 1968), particularly Chapters 1, 3, 4, 6, 7, and 9; xe2x80x9cThe Chemistry of Heterocyclic Compounds, A series of Monographsxe2x80x9d (John Wiley and Sons, New York, 1950 to present), in particular Volumes 13, 14, 16, 19, and 28; and xe2x80x9cJ. Am. Chem. Soc.xe2x80x9d, 82:5566 (1960). Exemplary monocyclic heterocyclyl rings include piperidyl, pyrrolidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, 1,3-dioxolanyl, 1,4-dioxanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, and the like.
The term xe2x80x9camino acidxe2x80x9d as used herein means an organic compound containing both a basic amino group and an acidic carboxyl group. Included within this term are natural amino acids (e.g., L-amino acids), modified and unusual amino acids (e.g., D-amino acids), as well as amino acids which are known to occur biologically in free or combined form but usually do not occur in proteins. Included within this term are modified and unusual amino acids, such as those disclosed in, for example, Roberts and Vellaccio (1983) The Peptides, 5: 342-429, the teaching of which is hereby incorporated by reference. Natural protein occurring amino acids include, but are not limited to, alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, serine, threonine, tyrosine, tyrosine, tryptophan, proline, and valine. Natural nonxe2x80x94protein amino acids include, but are not limited to arginosuccinic acid, citrulline, cysteine sulfinic acid, 3,4-dihydroxyphenylalanine, homocysteine, homoserine, ornithine, 3-monoiodotyrosine, 3,5-diiodotryosine, 3,5,5xe2x80x2-triiodothyronine, and 3,3xe2x80x2,5,5xe2x80x2-tetraiodothyronine. Modified or unusual amino acids which can be used to practice the invention include, but are not limited to, D-amino acids, hydroxylysine, 4-hydroxyproline, an Nxe2x80x94Cbz-protected amino acid, 2,4-diaminobutyric acid, homoarginine, norleucine, N-methylaminobutyric acid, naphthylalanine, phenylglycine, xcex2-phenylproline, tert-leucine, 4-aminocyclohexylalanine, N-methyl-norleucine, 3,4-dehydroproline, N,N-dimethylaminoglycine, N-methylaminoglycine, 4-aminopiperidine-4-carboxylic acid, 6-aminocaproic acid, trans-4-(aminomethyl)-cyclohexanecarboxylic acid, 2-, 3-, and 4-(aminomethyl)-benzoic acid, 1-aminocyclopentanecarboxylic acid, 1-aminocyclopropanecarboxylic acid, and 2-benzyl-5-aminopentanoic acid.
The term xe2x80x9cpeptidexe2x80x9d as used herein means a linear compound that consists of two or more amino acids (as defined herein) that are linked by means of a peptide bond. A xe2x80x9cpeptidexe2x80x9d as used in the presently claimed invention is intended to refer to a moiety with a molecular weight of less than 10,000 Daltons, preferable less than 5,000 Daltons, and more preferably less than 2,500 Daltons. The term xe2x80x9cpeptidexe2x80x9d also includes compounds containing both peptide and nonxe2x80x94peptide components, such as pseudopeptide or peptidomimetic residues or other non-amino acid components. Such a compound containing both peptide and non-peptide components may also be referred to as a xe2x80x9cpeptide analogxe2x80x9d.
A xe2x80x9cpseudopeptidexe2x80x9d or xe2x80x9cpeptidomimeticxe2x80x9d is a compound which mimics the structure of an amino acid residue or a peptide, for example, by using linking groups other than amide linkages between the peptide mimetic and an amino acid residue (pseudopeptide bonds) and/or by using non-amino acid substituents and/or a modified amino acid residue. A xe2x80x9cpseudopeptide residuexe2x80x9d means that portion of an pseudopeptide or peptidomimetic that is present in a peptide.
The term xe2x80x9cpeptide bondxe2x80x9d means a covalent amide linkage formed by loss of a molecule of water between the carboxyl group of one amino acid and the amino group of a second amino acid.
The term xe2x80x9cpseudopeptide bondsxe2x80x9d includes peptide bond isosteres which may be used in place of or as substitutes for the normal amide linkage. These substitute or amide xe2x80x9cequivalentxe2x80x9d linkages are formed from combinations of atoms not normally found in peptides or proteins which mimic the spatial requirements of the amide bond and which should stabilize the molecule to enzymatic degradation.
The phrase xe2x80x9cpharmaceutically acceptablexe2x80x9d is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
As used herein, xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; and alkali or organic salts of acidic residues such as carboxylic acids. The pharmaceutically acceptable salts include the conventional non-toxic salts or the quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, and nitric; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, and isethionic.
The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington""s Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418, the disclosure of which is hereby incorporated by reference.
The term xe2x80x9cpharmaceutically acceptable prodrugsxe2x80x9d as used herein means those prodrugs of the compounds useful according to the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention. The term xe2x80x9cprodrugxe2x80x9d means compounds that are rapidly transformed in vivo to yield the parent compound of the above formula, for example by hydrolysis in blood. Functional groups which may be rapidly transformed, by metabolic cleavage, in vivo form a class of groups reactive with the carboxyl group of the compounds of this invention. They include, but are not limited to such groups as alkanoyl (such as acetyl, propionyl, butyryl, and the like), unsubstituted and substituted aroyl (such as benzoyl and substituted benzoyl), alkoxycarbonyl (such as ethoxycarbonyl), trialkylsilyl (such as trimethyl- and triethysilyl), monoesters formed with dicarboxylic acids (such as succinyl), and the like. Because of the ease with which the metabolically cleavable groups of the compounds useful according to this invention are cleaved in vivo, the compounds bearing such groups act as pro-drugs. The compounds bearing the metabolically cleavable groups have the advantage that they may exhibit improved bioavailability as a result of enhanced solubility and/or rate of absorption conferred upon the parent compound by virtue of the presence of the metabolically cleavable group. Prodrugs include compounds of the present invention wherein a hydroxy, amino, or sulfhydryl group is bonded to any group that, when the prodrug of the present invention is administered to a mammalian subject, it cleaves to form a free hydroxyl, free amino, or free sulfhydryl group, respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups in the compounds of the present invention. A thorough discussion of prodrugs is provided in the following: Design of Prodrugs, H. Bundgaard, ed., Elsevier, 1985; Methods in Enzymology, K. Widder et al, Ed., Academic Press, 42, p.309-396, 1985; A Textbook of Drug Design and Development, Krogsgaard-Larsen and H. Bundgaard, ed., Chapter 5; xe2x80x9cDesign and Applications of Prodrugsxe2x80x9d p.113-191, 1991; Advanced Drug Delivery Reviews, H. Bundgard, 8, p.1-38, 1992; Journal of Pharmaceutical Sciences, 77, p. 285, 1988; Chem. Pharm. Bull., N. Nakeya et al, 32, p. 692, 1984; Pro-drugs as Novel Delivery Systems, T. Higuchi and V. Stella, Vol. 14 of the A.C.S. Symposium Series, and Bioreversible Carriers in Drug Design, Edward B. Roche, ed., American Pharmaceutical Association and Pergamon Press, 1987, which are incorporated herein by reference.
xe2x80x9cStable compoundxe2x80x9d and xe2x80x9cstable structurexe2x80x9d are meant to indicate a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic or diagnostic agent.
The biologically active molecule Q can be a protein, antibody, antibody fragment, peptide or polypeptide, or peptidomimetic that is comprised of a recognition sequence or unit for a receptor or binding site expressed at the site of the disease, or for a receptor or binding site expressed on platelets or leukocytes. The exact chemical composition of Q is selected based on the disease state to be diagnosed, the mechanism of localization to be utilized, and to provide an optimal combination of rates of localization, clearance and radio-decay.
For the purposes of this invention, the term thromboembolic disease is taken to include both venous and arterial disorders and pulmonary embolism, resulting from the formation of blood clots.
For the diagnosis of thromboembolic disorders or atherosclerosis, Q is selected from the group including the cyclic IIb/IIIa receptor antagonist compounds described in co-pending U.S. Ser. No.08/218,861 (equivalent to WO 94/22494); the RGD containing peptides described in U.S. Pat. Nos. 4,578,079, 4,792,525, the applications PCT US88/04403, PCT US89/01742, PCT US90/03788, PCT US91/02356 and by Ojima et. al., 204th Meeting of the Amer. Chem. Soc., 1992, Abstract 44; the peptides that are fibrinogen receptor antagonists described in European Patent Applications 90202015.5, 90202030.4, 90202032.2, 90202032.0, 90311148.2, 90311151.6, 90311537.6, the specific binding peptides and polypeptides described as IIb/IIIa receptor ligands, ligands for the polymerization site of fibrin, laminin derivatives, ligands for fibrinogen, or thrombin ligands in PCT WO 93/23085 (excluding the technetium binding groups); the oligopeptides that correspond to the IIIa protein described in PCT WO90/00178; the hirudin-based peptides described in PCT WO90/03391; the IIb/IIIa receptor ligands described in PCT WO90/15818; the thrombus, platelet binding or atherosclerotic plaque binding peptides described in PCT WO92/13572 (excluding the technetium binding group) or GB 9313965.7; the fibrin binding peptides described in U.S. Pat. Nos. 4,427,646 and 5,270,030; the hirudin-based peptides described in U.S. Pat. No. 5,279,812; or the fibrin binding proteins described in U.S. Pat. No. 5,217,705; the guanine derivatives that bind to the IIb/IIIa receptor described in U.S. Pat. No. 5,086,069; or the tyrosine derivatives described in European Patent Application 0478328A1, and by Hartman et. al., J. Med. Chem., 1992, 35, 4640; or oxidized low density lipoprotein (LDL).
For the diagnosis of infection, inflammation or transplant rejection, Q is selected from the group including the leukocyte binding peptides described in PCT WO93/17719 (excluding the technetium binding group), PCT WO92/13572 (excluding the technetium binding group) or U.S. Ser. No. 08/140000; the chemotactic peptides described in Eur. Pat. Appl. 90108734.6 or A. Fischman et. al., Semin. Nuc. Med., 1994, 24, 154; or the leukostimulatory agents described in U.S. Pat. No. 5,277,892.
For the diagnosis of cancer, Q is selected from the group of somatostatin analogs described in UK Application 8927255.3 or PCT WO94/00489, the selectin binding peptides described in PCT WO94/05269, the biological-function domains described in PCT WO93/12819, Platelet Factor 4 or the growth factors (PDGF, EGF, FGF, TNF, MCSF or Il-8).
Q may also represent proteins, antibodies, antibody fragments, peptides, polypeptides, or peptidomimetics that bind to receptors or binding sites on other tissues, organs, enzymes or fluids. Examples include the xcex2-amyloid proteins that have been demonstrated to accumulate in patients with Alzheimer""s disease, atrial naturetic factor derived peptides that bind to myocardial and renal receptors, antimyosin antibodies that bind to areas of infarcted tissues, or nitroimidazole derivatives that localize in hypoxic areas in vivo.
The group Chxe2x80x2 is termed a hydrazido (of formula R40R41Nxe2x80x94Nxe2x95x90), or diazenido (formula R40Nxe2x95x90N+xe2x95x90 or R40Nxe2x95x90N(H)xe2x80x94) group and serves as the point of attachment of the radionuclide to the remainder of the radiopharmaceutical designated by the formula (Q)dxe2x80x2-Ln or (Q)dxe2x80x2. A diazenido group can be either terminal (only one atom of the group is bound to the radionuclide) or chelating. In order to have a chelating diazenido group at least one other atom of the group, located on R40, must also be bound to the radionuclide. The atoms bound to the metal are termed donor atoms.
The transition metal radionuclide, Mt, is selected from the group: 99mTc, 186Re and 188Re. For diagnostic purposes 99mTc is the preferred isotope. Its 6 hour half-life and 140 keV gamma ray emission energy are almost ideal for gamma scintigraphy using equipment and procedures well established for those skilled in the art. The rhenium isotopes also have gamma ray emission energies that are compatible with gamma scintigraphy, however, they also emit high energy beta particles that are more damaging to living tissues. These beta particle emissions can be utilized for therapeutic purposes, for example, cancer radiotherapy.
The coordination sphere of the radionuclide includes all the ligands or groups bound to the radionuclide. For a transition metal radionuclide, Mt, to be stable it typically has a coordination number (number of donor atoms) comprised of an integer greater than or equal to 4 and less than or equal to 8; that is there are 4 to 8 atoms bound to the metal and it is said to have a complete coordination sphere. The requisite coordination number for a stable radionuclide complex is determined by the identity of the radionuclide, its oxidation state, and the type of donor atoms. If the chelator or bonding unit Chxe2x80x2 does not provide all of the atoms necessary to stabilize the metal radionuclide by completing its coordination sphere, the coordination sphere is completed by donor atoms from other ligands, termed ancillary or coligands, which can also be either terminal or chelating.
A large number of ligands can serve as ancillary or coligands, the choice of which is determined by a variety of considerations such as the ease of synthesis of the radiopharmaceutical, the chemical and physical properties of the ancillary ligand, the rate of formation, the yield, and the number of isomeric forms of the resulting radiopharmaceuticals, the ability to administer said ancillary or co-ligand to a patient without adverse physiological consequences to said patient, and the compatibility of the ligand in a lyophilized kit formulation. The charge and lipophilicity of the ancillary ligand will effect the charge and lipophilicity of the radiopharmaceuticals. For example, the use of 4,5-dihydroxy-1,3-benzene disulfonate results in radiopharmaceuticals with an additional two anionic groups because the sulfonate groups will be anionic under physiological conditions. The use of N-alkyl substituted 3,4-hydroxypyridinones results in radiopharmaceuticals with varying degrees of lipophilicity depending on the size of the alkyl substituents.
The radiopharmaceuticals of the present invention are comprised of two types of ancillary or coligands designated AL1 and AL2. Ancillary ligands AL1 are comprised of two or more hard donor atoms such as oxygen and amine nitrogen (sp3 hydribidized). The donor atoms occupy at least two of the sites in the coordination sphere of the radionuclide metal, Mt; the ancillary ligand AL1 serves as one of the three ligands in the ternary ligand system. Examples of ancillary ligands AL1 include but are not limited to dioxygen ligands and functionalized aminocarboxylates. A large number of such ligands are available from commercial sources.
Ancillary dioxygen ligands include ligands that coordinate to the metal ion through at least two oxygen donor atoms. Examples include but are not limited to: glucoheptonate, gluconate, 2-hydroxyisobutyrate, lactate, tartrate, mannitol, glucarate, maltol, Kojic acid, 2,2-bis(hydroxymethyl)propionic acid, 4,5-dihydroxy-1,3-benzene disulfonate, or substituted or unsubstituted 1,2 or 3,4 hydroxypyridinones. (The names for the ligands in these examples refer to either the protonated or non-protonated forms of the ligands.)
Functionalized aminocarboxylates include ligands that have a combination of amine nitrogen and oxygen donor atoms. Examples include but are not limited to: iminodiacetic acid, 2,3-diaminopropionic acid, nitrilotriacetic acid, N,Nxe2x80x2-ethylenediamine diacetic acid, N,N,Nxe2x80x2-ethylenediaminetriacetic acid, hydroxyethyl-ethylenediamine triacetic acid, and N,Nxe2x80x2-ethylenediamine bis-hydroxyphenylglycine. (The names for the ligands in these examples refer to either the protonated or non-protonated forms of the ligands.)
A series of functionalized aminocarboxylates are disclosed by Bridger et. al. in U.S. Pat. No. 5,350,837, herein incorporated by reference, that result in improved rates of formation of technetium labeled hydrazino modified proteins. We have determined that certain of these aminocarboxylates result in improved yields of the radiopharmaceuticals of the present invention. The preferred ancillary ligands AL1 functionalized aminocarboxylates that are derivatives of glycine; the most preferred is tricine (tris(hydroxymethyl)methyl-glycine).
The second type of ancillary ligands AL2 are highly functionalized phosphines. Ligands AL2 are monodentate. The ancillary ligands AL2 may be substituted with alkyl, aryl, alkoxy, heterocycle, aralkyl, alkaryl and arylalkaryl groups and may or may not bear functional groups comprised of heteroatoms such as oxygen, nitrogen, phosphorus or sulfur. Examples of such functional groups include but are not limited to: hydroxyl, carboxyl, carboxamide, nitro, ether, ketone, amino, ammonium, sulfonate, sulfonamide, phosphonate, and phosphonamide. The functional groups may be chosen to alter the lipophilicity and water solubility of the ligands, which may affect the biological properties of the radiopharmaceuticals, such as altering the distribution into non-target tissues, cells or fluids, and the mechanism and rate of elimination from the body.
The radiopharmaceuticals of the present invention can be easily prepared by admixing a salt of a radionuclide, a reagent of Formula 2, an ancillary ligand AL1, an ancillary ligand AL2, and a reducing agent, in an aqueous solution at temperatures from room temperature to 100xc2x0 C.
(Q)dxe2x80x2Lnxe2x80x94Ch xe2x80x83xe2x80x83(2) 
and pharmaceutically acceptable salts thereof, wherein: Q, dxe2x80x2, Ln are as defined above, Ch is a radionuclide metal chelator selected from the group: R40R41Nxe2x80x94Nxe2x95x90C(C1-C3 alkyl)2 and R40NNH2xe2x80x94, and R40R41Nxe2x80x94Nxe2x95x90C(R80)(R81), and pharmaceutically acceptable salts thereof. The synthesis of reagents of formula 2 is described in Wo 94/22494 and in WO 96/40637.
When Ch is a hydrazone group, then it must first be converted to the free hydrazine of formula R40R41NNH2, which may or may not be protonated, prior to complexation with the metal radionuclide, Mt. The chelator or bonding unit, Chxe2x80x2 when bound to the metal radionuclide, Mt, is designated Chxe2x80x2. The conversion of the hydrazone group to the hydrazine can occur either prior to reaction with the radionuclide, in which case the radionuclide and the ancillary or coligand or ligands are combined not with the reagent but with a hydrolyzed form of the reagent bearing the chelator or bonding unit, Chxe2x80x2 or in the presence of the radionuclide in which case the reagent itself is combined with the radionuclide and the ancillary or coligand or ligands. In the latter case, the pH of the reaction mixture must be neutral or acidic.
Alternatively, the radiopharmaceuticals of the present invention can be prepared by first admixing a salt of a radionuclide, an ancillary ligand AL1, and a reducing agent in an aqueous solution at temperatures from room temperature to 100xc2x0 C. to form an intermediate radionuclide complex with the ancillary ligand AL1 then adding a reagent of Formula 2 and an ancillary ligand AL2 and reacting further at temperatures from room temperature to 100xc2x0 C.
Alternatively, the radiopharmaceuticals of the present invention can be prepared by first admixing a salt of a radionuclide, an ancillary ligand AL1, a reagent of Formula 2, and a reducing agent in an aqueous solution at temperatures from room temperature to 100xc2x0 C. to form an intermediate radionuclide complex, and then adding an ancillary ligand AL2 and reacting further at temperatures from room temperature to 100xc2x0 C.
The total time of preparation will vary depending on the radionuclide, the identities and amounts of the reactants and the procedure used for the preparation. The preparations may be complete, resulting in  greater than 80% yield of the radiopharmaceutical, in 1 minute or may require more time. If higher purity radiopharmaceuticals are needed or desired, the products can be purified by any of a number of techniques well known to those skilled in the art such as liquid chromatography, solid phase extraction, solvent extraction, dialysis or ultrafiltration.
The technetium and rhenium radionuclides are preferably in the chemical form of pertechnetate or perrhenate and a pharmaceutically acceptable cation. The pertechnetate salt form is preferably sodium pertechnetate such as obtained from commercial Tc-99m generators. The amount of pertechnetate used to prepare the radiopharmaceuticals of the present invention can range from 0.1 mCi to 1 Ci, or more preferably from 1 to 200 mCi.
The amount of the reagent of formula 2 used to prepare the radiopharmaceuticals of the present invention can range from 0.1 xcexcg to 10 mg, or more preferably from 0.5 xcexcg to 100 xcexcg. The amount used will be dictated by the amounts of the other reactants and the identity of the radiopharmaceuticals of Formula 1 to be prepared.
The amounts of the ancillary ligands AL1 used can range from 0.1 mg to 1 g, or more preferably from 1 mg to 100 mg. The exact amount for a particular radiopharmaceutical is a function of identity of the radiopharmaceuticals of Formula 1 to be prepared, the procedure used and the amounts and identities of the other reactants. Too large an amount of AL1 will result in the formation of by-products comprised of technetium labeled AL1 without a biologically active molecule or by-products comprised of technetium labeled biologically active molecules with the ancillary ligand AL1 but without the ancillary ligand AL2. Too small an amount of AL1 will result in other by-products such as technetium labeled biologically active molecules with the ancillary ligand AL2 but without the ancillary ligand AL1, or reduced hydrolyzed technetium, or technetium colloid.
The amounts of the ancillary ligands AL2 used can range from 1 mg to 1 g, or more preferably from 1 mg to 10 mg. The exact amount for a particular radiopharmaceutical is a function of the identity of the radiopharmaceuticals of Formula 1 to be prepared, the procedure used and the amounts and identities of the other reactants. Too large an amount of AL2 will result in the formation of by-products comprised of technetium labeled AL2 without a biologically active molecule or by-products comprised of technetium labeled biologically active molecules with the ancillary ligand AL2 but without the ancillary ligand AL1. If the moiety (Q)dxe2x80x2-Lnxe2x80x94Chxe2x80x2 bears one or more substituents that are comprised of a soft donor atom, as defined above, at least a ten-fold molar excess of the ancillary ligand AL2 to the reagent of formula 2 is required to prevent the substituent from interfering with the coordination of the ancillary ligand AL2 to the metal radionuclide, Mt.
Suitable reducing agents for the synthesis of the radiopharmaceuticals of the present invention include stannous salts, dithionite or bisulfite salts, borohydride salts, and formamidinesulfinic acid, wherein the salts are of any pharmaceutically acceptable form. The preferred reducing agent is a stannous salt. The amount of a reducing agent used can range from 0.001 mg to 10 mg, or more preferably from 0.005 mg to 1 mg.
The specific structure of a radiopharmaceutical of the present invention will depend on the identity of the biomolecule Q, the number dxe2x80x2, the identity of the linker Ln, the identity of the chelator moiety Chxe2x80x2, the identity of the ancillary ligand AL1, the identity of the ancillary ligand AL2, and the identity of the radionuclide Mt. The identities of Q, Ln, and Chxe2x80x2 and the number dxe2x80x2 are determined by the choice of the reagent of Formulae 2 or 3. For a given reagent of Formulae 2 or 3, the amount of the reagent, the amount and identity of the ancillary ligands AL1 and AL2, the identity of the radionuclide Mt and the synthesis conditions employed will determine the structure of the radiopharmaceutical of Formula 1.
Radiopharmaceuticals synthesized using concentrations of reagents of Formulae 2 or 3 of  less than 100 xcexcg/mL, will be comprised of one hydrazido or diazenido group Chxe2x80x2; the value of x will be 1. Those synthesized using  greater than 1 mg/mL concentrations will be comprised of two hydrazido or diazenido groups; the value of x will be 2. The two Chxe2x80x2 groups may be the same or different. For most applications, only a limited amount of the biologically active molecule can be injected and not result in undesired side-effects, such as chemical toxicity, interference with a biological process or an altered biodistribution of the radiopharmaceutical. Therefore, the radiopharmaceuticals with x equal to 2, which require higher concentrations of the reagents of Formula 2 comprised in part of the biologically active molecule, will have to be diluted or purified after synthesis to avoid such side-effects.
The identities and amounts used of the ancillary ligands AL1 and AL2 will determine the values of the variables y and z. The values of y and z can independently be an integer from 1 to 2. In combination, the values of y and z will result in a technetium coordination sphere that is made up of at least five and no more than seven donor atoms. For monodentate ancillary ligands AL2, z can be an integer from 1 to 2; for bidentate or tridentate ancillary ligands AL2, z is 1. The preferred combination for monodentate ligands is y equal to 1 or 2 and z equal to 1. The preferred combination for bidentate or tridentate ligands is y equal to 1 and z equal to 1.
Since prodrugs are known to enhance numerous desirable qualities of pharmaceuticals (e.g., solubility, bioavailability, manufacturing, etc. . . . ) the compounds of the present invention may be delivered in prodrug form. Thus, the present invention is intended to cover prodrugs of the presently claimed compounds, methods of delivering the same and compositions containing the same.
Another aspect of the present invention are diagnostic kits for the preparation of radiopharmaceuticals useful as imaging agents for the diagnosis of cardiovascular disorders, infectious disease, inflammatory disease and cancer. Diagnostic kits of the present invention comprise one or more vials containing the sterile, non-pyrogenic, formulation comprised of a predetermined amount of the reagent of formulae (Q)dxe2x80x2xe2x80x94Lnxe2x80x94Ch or (Q)dxe2x80x2xe2x80x94Lnxe2x80x94Hz, one or two ancillary or coligands and optionally other components such as reducing agents, transfer ligands, buffers, lyophilization aids, stabilization aids, solubilization aids and bacteriostats. The inclusion of one or more optional components in the formulation will frequently improve the ease of synthesis of the radiopharmaceutical by the practising end user, the ease of manufacturing the kit, the shelf-life of the kit, or the stability and shelf-life of the radiopharmaceutical. The improvement achieved by the inclusion of an optional component in the formulation must be weighed against the added complexity of the formulation and added cost to manufacture the kit. The one or more vials that contain all or part of the formulation can independently be in the form of a sterile solution or a lyophilized solid.
Buffers useful in the preparation of radiopharmaceuticals and in diagnostic kits useful for the preparation of said radiopharmaceuticals include but are not limited to phosphate, citrate, sulfosalicylate, and acetate. A more complete list can be found in the United States Pharmacopeia.
Lyophilization aids useful in the preparation of diagnostic kits useful for the preparation of radiopharmaceuticals include but are not limited to mannitol, lactose, sorbitol, dextran, Ficoll, and polyvinylpyrrolidine (PVP).
Stabilization aids useful in the preparation of radiopharmaceuticals and in diagnostic kits useful for the preparation of said radiopharmaceuticals include but are not limited to ascorbic acid, cysteine, monothioglycerol, sodium bisulfite, sodium metabisulfite, gentisic acid, and inositol.
Solubilization aids useful in the preparation of radiopharmaceuticals and in diagnostic kits useful for the preparation of said radiopharmaceuticals include but are not limited to ethanol, glycerin, polyethylene glycol, propylene glycol, polyoxyethylene sorbitan monooleate, sorbitan monoloeate, polysorbates, poly(oxyethylene)-poly(oxypropylene)poly(oxyethylene) block copolymers (Pluronics) and lecithin. Preferred solubilizing aids are polyethylene glycol, and Pluronics.
Bacteriostats useful in the preparation of radiopharmaceuticals and in diagnostic kits useful for the preparation of said radiopharmaceuticals include but are not limited to benzyl alcohol, benzalkonium chloride, chlorbutanol, and methyl, propyl or butyl paraben.
A component in a diagnostic kit can also serve more than one function. A reducing agent can also serve as a stabilization aid, a buffer can also serve as a transfer ligand, a lyophilization aid can also serve as a transfer, ancillary or coligand and so forth.
The predetermined amounts of each component in the formulation are determined by a variety of considerations that are in some cases specific for that component and in other cases dependent on the amount of another component or the presence and amount of an optional component. In general, the minimal amount of each component is used that will give the desired effect of the formulation. The desired effect of the formulation is that the practising end user can synthesize the radiopharmaceutical and have a high degree of certainty that the radiopharmaceutical can be safely injected into a patient and will provide diagnostic information about the disease state of that patient.
The diagnostic kits of the present invention will also contain written instructions for the practising end user to follow to synthesize the radiopharmaceuticals. These instructions may be affixed to one or more of the vials or to the container in which the vial or vials are packaged for shipping or may be a separate insert, termed the package insert.
Another aspect of the present invention contemplates a method of imaging the site of thrombotic disease in a patient involving: (1) synthesizing a radiopharmaceutical using a reagent of the present invention capable of localizing at sites of thrombotic disease due to an interaction between the biologically active group, Q, of the radiopharmaceutical and a receptor or binding site expressed at the site of the disease or with a receptor or binding site on an endogenous blood component that accumulates at the site; (2) administering said radiopharmaceutical to a patient by injection or infusion; (3) imaging the patient using either planar or SPECT gamma scintigraphy.
Another aspect of the present invention contemplates a method of imaging the site of infection or infectious disease in a patient involving: (1) synthesizing a radiopharmaceutical using a reagent of the present invention capable of localizing at sites of infection or infectious disease due to an interaction between the biologically active group, Q, of the radiopharmaceutical and a receptor or binding site expressed at the site of the disease or with a receptor or binding site on an endogenous blood component that accumulates at the site; (2) administering said radiopharmaceutical to a patient by injection or infusion; (3) imaging the patient using either planar or SPECT gamma scintigraphy.
Another aspect of the present invention contemplates a method of imaging the site of inflammation in a patient involving: (1) synthesizing a radiopharmaceutical using a reagent of the present invention capable of localizing at sites of inflammation due to an interaction between the biologically active group, Q, of the radiopharmaceutical and a receptor or binding site expressed at the site of inflammation or with a receptor or binding site on an endogenous blood component that accumulates at the site; (2) administering said radiopharmaceutical to a patient by injection or infusion; (3) imaging the patient using either planar or SPECT gamma scintigraphy.
Another aspect of the present invention contemplates a method of imaging the site of cancer in a patient involving: (1) synthesizing a radiopharmaceutical using a reagent of the present invention capable of localizing at sites of cancer due to an interaction between the biomolecule, Q, of the radiopharmaceutical and a receptor or binding site expressed at the site of the cancer or with a receptor or binding site on an endogenous blood component that accumulates at the site; (2) administering said radiopharmaceutical to a patient by injection or infusion; (3) imaging the patient using either planar or SPECT gamma scintigraphy.
The radiopharmaceuticals are administered by intravenous injection, usually in saline solution, at a dose of 1 to 100 mCi per 70 kg body weight, or preferably at a dose of 5 to 50 mCi. Imaging is performed using known procedures.
The compounds herein described may have asymmetric centers. Compounds of the present invention containing an asymmetrically substituted atom may be isolated in optically active or racemic forms. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis from optically active starting materials. Many geometric isomers of olefins, Cxe2x95x90N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. Cis and trans geometric isomers of the compounds of the present invention are described and may be isolated as a mixture of isomers or as separated isomeric forms. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomeric form is specifically indicated. All processes used to prepare compounds of the present invention and intermediates made therein are considered to be part of the present invention. The term xe2x80x9csubstituted,xe2x80x9d as used herein, means that any one or more hydrogens on the designated atom is replaced with a selection from the indicated group, provided that the designated atom""s normal valency is not exceeded, and that the substitution results in a stable compound. When a substitent is keto (i.e., xe2x95x90O), then 2 hydrogens on the atom are replaced. Keto substituents are not present on aromatic moieties. When a ring system (e.g., carbocyclic or heterocyclic) is said to be substituted with a carbonyl group or a double bond, it is intended that the carbonyl group or double bond be part (i.e., within) of the ring.
The present invention is intended to include all isotopes of atoms occurring in the present compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include tritium and deuterium. Isotopes of carbon include C-13 and C-14.
When any variable (e.g., R6) occurs more than one time in any constituent or formula for a compound, its definition at each occurrence is independent of its definition at every other occurrence. Thus, for example, if a group is shown to be substituted with 0-2 R6, then said group may optionally be substituted with up to two R6 groups and R6 at each occurrence is selected independently from the definition of R6. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
When a bond to a substituent is shown to cross a bond connecting two atoms in a ring, then such substituent may be bonded to any atom on the ring. When a substituent is listed without indicating the atom via which such substituent is bonded to the rest of the compound of a given formula, then such substituent may be bonded via any atom in such substituent. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
Other features of the invention will become apparent in the course of the following descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.